1. Field of the Invention
Aspects of the present invention relate to a camera and a photographing method thereof, and more particularly, to a camera which is capable of photographing an object more efficiently and a photographing method thereof.
2. Description of the Related Art
Methods for displaying a photographed image signal on a screen include a method using an interlaced scan and a method using a progressive scan. The progressive scan is used in a computer monitor, a digital TV, and a digital video recorder (DVR), and displays lines in sequence as a single image frame, as if a film is projected onto a screen.
In contrast, the interlaced scan is used in a general TV and a camera. The interlaced scan divides a single image frame into two fields and displays the two fields in an alternating fashion to display a single image. The interlaced scan outputs scan lines, for examples, 525 lines for the National Television System Committee (NTSC) system and 625 lines for the Phase Alternating Line (PAL) system, on a screen in 1/60 of a second intervals. That is, the interlaced scan outputs even-numbered scan lines in 1/60 of a second intervals and then outputs odd-numbered scan lines in 1/60 of a second intervals. Each scene in 1/60 of a second intervals is called a field and the added two fields are output in 1/30 of a second intervals and called a frame.
However, the interlaced scan adds the two fields to form a singe frame, and therefore, if there is a movement of an object between fields, the interlaced scan adds two sheets of image created at the different times to form a single frame. This movement causes a noise in contours of the image. In particular, if an object moving at high speed is photographed in the interlaced scan, a movement difference of the object between fields is great. Thus, image quality is degraded when the single frame is formed.
Also, the progressive scan generates a small number of frames per second, compared to the interlaced scan. Accordingly, if a specific portion of an object moving at high speed is photographed in the progressive scan, it is difficult to photograph the specific portion of the object due to the object's high speed movement.